A fan type chemical volatilizing and diffusing apparatus has been known which is designed to diffuse into the atmosphere, e.g., in a room an active ingredient of a volatile chemical such as an insecticide, insect repellent or moth-proofing agent, aromatic chemical and deodorant by the force of a wind.
This typical fan type chemical volatilizing and diffusing apparatus is provided with an air inlet for admitting air from the outside into the apparatus body and an air outlet for sending out air admitted. In the air flow passage between the air inlet and the air outlet there are mounted a fan type blower driven by a motor and an active ingredient carrier body impregnated with an active ingredient. Provided also in the apparatus body is a room for accommodating a battery for powering the motor and hence the fan blower.
The active ingredient impregnated body is disposed either in the air flow passage between the air inlet and the fan or in the air flow passage between the fan and the air outlet. Thus, the apparatus is of the type in which rotating the fan to send air causes the active ingredient in the impregnated body to diffuse through the air outlet into the atmosphere.
As shown in JP U H06-4393A, another fan type chemical diffusing apparatus has been known in which the fan in a fan type blower itself contains a volatile chemical.
The typical fan type chemical diffusing apparatus mentioned above is provided with the fan type blower and the active ingredient impregnated body separately in the apparatus body and formed with an air flow passage in the apparatus body. As a result, it is forced to be complex in structure and makes the apparatus large in size.
The requirement that the active ingredient impregnated body and the fan be arranged to efficiently send air into, through and out of the active ingredient impregnated body tends to make the apparatus structure complex and large in size.
If the apparatus is to be powered by a battery, providing a space for accommodating the battery in the apparatus makes the apparatus even more complex and larger in size.
It should be noted in particular that the site in which the active ingredient impregnated body is placed determines the size of the apparatus and a degree of its complexity.
The fan type chemical diffusing apparatus disclosed in JP U H06-4393A by having the fan effectively functioning as the active ingredient impregnated body seeks to resolve the problem of how it can efficiently be arranged and to simplify the apparatus structure. However, many problems still remain unresolved, for example, as regards an unsatisfactory durability (e.g., brittleness) of the fan which must be made by forming, a limited impregnable amount (small amount) of an active ingredient and, if the fan is of replacement type, the time, labor and cost entailed for replacement, which may make the apparatus poor in utility and serviceability.
As an example of the fan type chemical diffusing apparatus using a fan type blower, a debugging apparatus of first type for repelling and exterminating or excluding a noxious or harmful insect has also been disclosed which is designed to volatilize a chemical by providing an air flow through the chemical by means of a fan blower driven by a motor. See, for example, JP P S53-14329A, JP U S61-182273A, JP U H06-75179A, WO96/04786, JP P H08-154554A, JP P H11-504627A and JP P H11-28040A.
As another example as disclosed in JP P H05-68459A, a debugging apparatus of second type has also been disclosed in which a volatile chemical is retained within the chemical diffusing fan which may be rotated to volatilize the chemical.
Further, as another example, a third type of debugging apparatus has been known as disclosed in JP P H07-111850A, a third type of debugging apparatus has been disclosed in which a carrier impregnated with a chemical and also functioning to rectify a gas flow is disposed in the air intake side of a fan which may be rotated to cause an air flow created to volatilize the chemical.
The first type debugging apparatus seems to lack concreteness and seems to have many problems to be resolved for practical use.
The second type debugging apparatus is technologically concrete and practical but if ever practiced seems to lack flexibility. A need to make the retainer larger in size in order to volatilize a larger amount of a chemical proportionally increases energy needed to drive the fan.
The third type debugging apparatus is technologically concrete and practical but is noted to require the carrier not only to be larger in area but to have a shape suitable to reduce air resistance as much as possible. As the present inventors' scrutiny indicates, the idea of requiring the active ingredient impregnated body to be larger in area in order to volatilize a larger amount of the active ingredient must be justified. But, the idea of requiring it to be shaped so as to reduce wind resistance as much as possible was found much questionable.
For to remove wind resistance means reducing wind pressure per unit area and this would reduce a force to detach the chemical from the carrier. Then, the phenomenon would take place that the wind passes away from the carrier without enough carrying the chemical, or a reduction in chemical concentration per unit air flow. This is a loss in wind force and in other words a loss in driving energy.
In contrast, excessively increasing air resistance would reduce the wind speed of a wind coming out of the air outlet and lose the capacity to carry the chemical far.
As an example of the debugging apparatus using a fan type blower, a fourth type of such apparatus has also been proposed which is designed to volatilize a chemical by providing an air flow through the chemical by means of a fan blower driven by a motor. See, for example, JP P S53-14329A, JP U S61-182273A, JP U H06-75179A, WO96/04786, JP P H08-154554 and JP P H11-504627A.
Further, as another example, a fifth type of debugging apparatus has also been proposed as disclosed in JP P H11-28040A which comprises a DC motor powered by a battery and a fan to be driven by the DC motor to provide an air flow through a chemical for its volatilization.
The fourth type debugging apparatus seems to lack concreteness for using a battery as power supply and seems to have many problems to be resolved for practical use.
The fifth type debugging apparatus is an apparatus with a battery as power supply and is shown in its second apparatus to have a current consumption of not greater than 100 milliamperes when the DC motor is unloaded. However, no consideration appears to be taken, e.g., in efficiently using the battery to allow the chemical to be volatilized for a prolonged time period.
Thus, a fan type debugging apparatus for repelling and excluding harmful or noxious insects as previously described is used as placed on a storage space in a house in order to run over a long period of time or as carried by a worker for use to run outdoors. It is therefore desirable that the apparatus have the ability to volatilize a chemical for a long time without the need to change the battery.
Another example of the fan type debugging apparatus has also been known as disclosed, for example, in JP P H11-308955A.
This fan type debugging apparatus has an apparatus body provided with a motor, a fan, a battery and a chemical retainer and is operable to provide an air flow through the chemical retainer from the fun by driving the motor with the battery power to volatilize the chemical. It is shown that the motor is intermittently operated to iteratively have a time period of air flow and a time period of halt alternately with the time period of halt being ten times or more as long as the time period of air flow.
The fan type debugging apparatus referred to above is designed for use as placed in a storage space such as a wardrobe or closet and is there found to extend the debugging component enough inside the closed space and capable of maintaining its efficacy enough for a long time.
However, using this type of apparatus as placed in a living space in a dwelling proves it insufficiently efficacious.
There have also bee known chemical volatilizing and diffusing methods using the wind force of a fan to volatilize and diffuse a volatile chemical into the atmosphere. For example, JP U S61-182273A discloses applying a wind from the fan to a chemical impregnated retainer body having a moderate air permeability, and JP P H07-11850A discloses defining a relationship between a fan's wind force and a permeability.
To the present inventors' knowledge, all the chemical impregnated or retainer bodies (active ingredient impregnated bodies) so far proposed in the prior art are bodies which are solidified and monolithic. For this reason, they provide an effective means if chemicals to be carried thereby are high in vapor pressure and thus highly volatile. If a need arises to volatilize a chemical which is less volatile or hard to volatilize or to volatilize a plenty of a chemical at a time, it has become necessary to take a measure such as: (1) to make larger the area of volatilization of a chemical impregnated body; (2) to make larger voids in a chemical impregnated body to facilitate wind passage; and to intensify the fan's output.
It has been found, however, that any of these measure cannot be taken without making larger the entire volume of the chemical impregnated body, or without making the fan larger in size or deteriorating energy efficiency. Especially, an increase of the chemical impregnated body in size brings about the problems as follows:                (1) Local changes in air flow within the chemical impregnated body. Thus, as it becomes distant especially from the wind blow outlet, the air flow per unit time tends to be reduced by an air resistance that develops in the chemical impregnated body. If the chemical impregnated body is larger in the direction of the wind, the wind force which the chemical impregnated body instantaneously receives varies from one site to another. This leads to an unbalance of volatilization over the entire impregnated body and prevents the chemical from volatilizing stably.        (2) Even if the situation (1) develops, stable volatilization will be possible even for the solidified, monolithic chemical impregnated body if the chemical impregnated is quickly made even in the body. However, increase in the size of the chemical impregnated body makes longer the distance for the chemical to move and requires longer time for the chemical to be made even in the body.        (3) An increase in size of the chemical impregnated body for the reason of the problem mentioned at (1) above also brings about a drop in the air flow per unit time from the air outlets (volatilization outlets) of the chemical impregnated body receptacle, which leads to a drop in the ability of the chemical to volatilize into a room and in turn to a drop in the efficacy of the chemical. Made to resolve these problems, an attempt to intensify the fan's wind force is an attempt to waste energy and proves inefficient and uneconomical.        
Accordingly, it is an object of the present invention to provide a fan type chemical diffusing apparatus that can resolve one or more of the problems mentioned earlier.
It is also an object of the present invention to provide a fan type debugging apparatus for repelling and exterminating or expelling a noxious or harmful insect that permits an active ingredient to be volatilized in a maximum amount with a minimum input driving energy.
It is also an object of the present invention to provide a fan type debugging apparatus operated with a battery which permit a chemical to be volatilized over a prolonged time period without the need to exchange the battery.
It is also an object of the present invention to provide a fan type debugging apparatus usable in a living space, proving a sufficient efficacy and capable of maintaining the sufficient efficacy for a prolonged time period.
It is also an object of the present invention to provide a chemical volatilizing method that permits a volatile chemical having insecticide, insect repellent or growth control function to be diffused and dispersed stably by a wind force over a prolonged time period for a variety of noxious or harmful insects, regardless of the vapor pressure the chemical possesses and the amount of volatilization the chemical is aimed for.